Device for regulating alternating currents



May 10, 1932. N A. J. VOORHOEVE 1,357,575

DEVICE FOR REGULATING ALTERNATING CURRENTS Filed April 19, 1927 M or/1oave Patented May It, 1932 PATENT OFFICE NIGOLAAS ANTHONY J'OHANNESVOORHOEVE, F EINDHOVEN, NETHERLANDS, AS- SIGNOR TO N. V. PHILIPSGLOEILAMPENFABRIEKEN, 0F EINDHOVEN, NETHER- LANDS, A LIMITED LIABILITYCOMPANY OF THE NETHERLANDS DEVICE FOR REGULATING ALTERNATING- (TURIRENTSApplication filed April 19, 1927, Serial No. 185,059, and in theNetherlands May 20, 1926.

This invention has reference to a device for regulating alternatingvoltages in which the regulation ensues as a result of load variations.

It has already been known from the French patent specification .No.543,765 to regulate a varying working voltage by means of transformersand electron discharge devices in such manner that, if the workingvoltage dem creases, an auxiliary voltage has been added thereto andreverted.

Such a device has for its object to permit a constant working voltage tobe taken ofi of a varying supply voltage. It also pro- I vides for thecase in which the working voltage is influenced by load impulses.

In this case the filament heating temperature is regulated by theworking voltage and the anode current flows in such manner through thetransformer coil, that it excites in it a voltage which is opposed tothe voltage prevailing in the second transformer coil, which is directlytraversed by the supply current. Thus a reciprocal is insured by 5reason of the fact that owing to an increase of the supply voltage thecounteracting volt-- age. mcreases and ]11st keeps the voltage in theload current circuit constant.

According to the invention this is insured so by means of a device forregulating alternating voltages in which a variable auxiliary voltage isexcited between the source of current and the load by one or moreboostertransformers in such manner that the voltage at the load has apreviously determinable characteristic, in that said auxiliary voltagenected. The load is connected to terminals 1 1 and 2. The numerals 5 and8 designate interconnected transformers, the last named of which has twosecondaries 6 and 7 which supply the filament heating current fordischarge tubes 3 and 4. 9 and 10 are resistances for controlling thefilament heating currents.

The schematic circuit diagram shown in Fig. 2 corresponds approximatelyto that of Fig. 1 but shows a modification.

The regulating action according to the invention will now be explainedby reference to Fig. 1. Assume the supply voltage E to be increasing. Inthe first instant the load voltage will also increase. This causes anincrease in supply voltage of the filaments of the tubes 3 and 4 as thefilament heating transformer 8 is indirectly connected to the loadvoltage.

The impedance of the discharge tubes 3 and 4 will therefore decrease andhence more current will be flowing through the winding 5".

If the auxiliary voltage which will be induced in the winding 5 by thewinding 5",

is opposite to the supply voltage, the increase of the supply voltagewill be opposed. It can be so regulated that it neutralizes the increasein supply voltage so that the load voltage remains about constant. Thesame will occur when the load current I increases. case the auxiliaryvoltage m the wind- In this ing 5 will nearly balance out the auxiliarypotential drop in this winding.

The action of the circuit arrangement of Figure 2 in which like numeralsrefer to the the anode current thereof increases.

nected that as a result the working voltage also decreases so that thelatter remains substantially constant.

Now assuming that the load current is increasing, in that case theworking voltage will decrease. The impedance of the discharge tubesincreases as a result of the decrease of the filament heating current.The anode current of the tubes decreases and the current through theprimary 5 of the transformer 5 increases. The voltage on the coil 5consequently rises and as stated above, the latter is so connected thatthe working voltage increases again. This increase is so regulated thatit compensates the decrease of working voltage due to the increase ofthe load current.

Itis to be noted that in this last case (Fig.

' 1) an increase in the load voltage will give an increase in currentflowing through winding 5". In the arrangement shown in Fig.2 anincrease in load voltage will cause a decrease of this current.Accordingly the connection of the winding 5 in Fig. 2 must be exactlythe reverse as in Figure 2, so that the voltage induced in the winding5' will be in the right direction.

It is obvious that the invention is susceptible to numerousmodifications and adapta tions without departing from the spiritthereof, and it is intended that the invention be limited only by thescope of the appended claims.

What I claim is:

' 1. A device for regulating alternating voltages, comprising mainleads, a load connected across said leads, two oppositely connecteddischarge tubes, the said tubes being connected in parallel, atransformer, the secondary winding of said transformer being inserted inone of the leads to the load, and theprimary winding thereof beingincluded in a circuit which also comprises the said parallel connectedtubes, said circuit being connected across the said main leads, and asecond transformer, having its primary winding connected between saidleads, the said transformer having two secondary windings each connectedto the filament of a corresponding one of the said discharge tubes.

2. A device for regulating alternating voltages, comprising main leads,a load connected across said leads two oppositely connected dischargetubes, the said tubes being connected in parallel, a,transformer, thesecondary winding of said transformer being inserted in one of the leadsto the load and the primary winding thereof being connected in serieswith the said tubes, the said series combination being connected acrossthe said main leads, and a second transformer having its primary windingconnected between the said leads, the said transformer having twosecondary windings each connected to the filament of a corresponding oneof the said discharge tubes.

3. A device for regulating alternating voltages, comprising main leads,a load connected across said leads, two oppositely connected dischargetubes, the said tubes being connected in parallel, a transformer, thesecondary winding of the said transformer being inserted in one of theleads to the load, and the pri- J

